<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>


<style>
    body>*{
        width: 95%px; height: auto; margin:0 auto;margin-top: 10px;
        border: 1px solid #000; padding: 5px;
    }
    header{height: 50px;}
    section{height: 300px;}
    footer{height: 30px;}
    section>*{height: 100%;border:1px solid #000;float:left}
    aside{width: 25%;}
    article{width: 70%;margin-left:1%;}
    </style>
<body>
    <header>header</header>
    <nav>nav</nav>
    <section>
        <aside>aside</aside>
    <article>article</article>
    </section>
    <footer>footer</footer>
</body>
</html>